The present invention relates generally to stethoscopes and, more particularly, to chestpieces for stethoscopes, especially electronic stethoscopes having operational controls located on the chestpiece.
Stethoscopes have long been used by physicians to monitor auscultatory sounds. Typically stethoscopes have been comprised of a head or chestpiece, a sound transmission mechanism and an earpiece assembly. The chestpiece is adapted to be placed against the skin of a patient for gathering the auscultatory sounds. The sound transmission mechanism transmits the gathered sound to the earpiece where the physician may monitor the sound.
The chestpiece of conventional auditory stethoscopes are usually quite simple physically. They are usually round disk shapes sometimes dual sided, top and bottom, to allow either side of the chestpiece to contact the skin of the patient, perhaps for the gathering of auscultatory sounds in different frequency ranges.
U.S. Pat. No. 4,071,694, Pfeiffer, Stethoscope, (assigned to the assignee of the present invention) describes a stethoscope which has both an electronic and an acoustic capability. The chestpiece of the stethoscope described in the Pfeiffer patent has a conventional shape and achieves a conventional function. The chestpiece is round and generally flat making the stethoscope appear and handle similarly, and has ergonometrics similar to, conventional stethoscopes.
Recently, the auditory sound gathering, transmission and delivery functions of stethoscopes have been supplemented or supplanted by electronic gathering or transmission.
The incorporation of electronic circuitry into the stethoscope has been a considerable design problem for the engineer. Typically, the electronic circuitry increases the physical size of the stethoscope package. Either the size of the chestpiece is increased in size dramatically or an additional enclosure to house the electronics is located between the chestpiece and earpiece assembly or both. In both of these cases, the resulting stethoscope is bulky, cumbersome to use and not easily storable between uses. The result, thus, is a stethoscope which is distinctly not ergonometric.
The problem of making a stethoscope, especially an electronic stethoscope ergonometric can be seen by reference to U.S. Pat. No. 3,790,712, Andries, Electronic Stethoscope System. The Andries patent describes an electronic stethoscope which has a chestpiece sized and shaped like a large rectangular, cumbersome box. This large, cumbersome box houses the electronic circuitry of the stethoscope. The box has a projecting member 15 with a forward lip portion 16 for engagement with a skin surface. This projecting member 15 has a conically shaped interior wall with a centrally located sound opening 18.
The stethoscope described in U.S. Pat. No. 4,170,717, Walshe, Electronic Stethoscope, has a chestpiece having an elongated housing 20 carrying a body piece 21 which includes an annular ring 21a to be placed against a patient's body. A thin diaphragm 22 extends across the opening formed by ring 21a and is acoustically coupled to a microphone 23. Again, the chestpiece of the stethoscope described in Walshe '717 is large, bulky and has a generally elongated rectangular shape rounded on one end.
The chestpiece 120 of the stethoscope described in U.S. Pat. No. 4,254,302, Walshe, Electronic Stethoscope, has an annular upper portion 160, a relatively larger annular lower portion 161 and a reduced diameter immediate control portion 162 adapted to be interdigitally grasped, particularly with the doctor's first and second fingers. The controls of the electronic stethoscope are positioned on the reduced diameter immediate control portion 162 for protection.
The stethoscope described in U.S. Pat. No. 4,723,555, Shue, Multi-Functional Radio/Wire Stethoscope Apparatus, and U.S. Pat. No. 4,878,501, Shue, Multi-Functional Radio/Wire Stethoscope Apparatus, has a chestpiece with a diaphragm on one side and a bell on the other designed for gathering auscultatory sounds. The chestpiece generally is shaped to have a truncated cone on each side with the open end of the cone adapted for contacting the patient's skin. The truncated section of the cones are coupled together with a cylinder forming a circular portion with a smaller diameter than the open end of the cones.
U.S. Pat. No. 4,440,258, Packard, Tunable Stethoscope, (assigned to the assignee of the present invention) describes a stethoscope with a chestpiece (stethoscope head) having a body member having a first generally bell-shaped recess, a diaphragm, a suspension member for connecting the diaphragm to the body member, and an immobilizing means located within the first recess. The suspension member affords movement of the diaphragm in a direction generally perpendicular to the plane of the diaphragm without the shape of or lateral tension in the diaphragm changing substantially. The movement of the diaphragm allows the stethoscope to be tunable with respect to auscultatory sounds.
The chestpiece of the stethoscope described in the Packard patent has a body member 11 formed of conventional material. The body member 11 has a substantially disk like portion 18 and a column 19 emanating therefrom. The top 20 of column 19 is substantially flat. Front section 21 of column 19 is sloped away from top 20, is concave in configuration and is curved to meet the top surface of disk like portion 18. Side sections 22 and 23 and back section 24 are arcuate in configuration. The shape of body member 11 permits the physician to grasp column 19 from the top with the index finger being placed on front section 21 and each of the thumb and the middle finger adjacent disk 18 on opposite sides of column 19 with a fitting 15 passing between those fingers.
The column 19 of the chestpiece of the stethoscope described in the Packard patent allows the chestpiece to be easily grasped by the physician. The column 19 is generally cylindrical with concave side walls. The cylindrical shape of column 19 limits the precise positioning and indexing of the fingers and space for positioning controls and indicators.